Final answer:
The most dramatic increase in the incidence of type 2 diabetes over the past two decades has involved children and adolescents.
Step-by-step explanation:
The most dramatic increase in the incidence of type 2 diabetes over the past two decades has involved children and adolescents. Previously, type 2 diabetes typically started after the age of 40 and was more common in middle-aged individuals and older adults. However, due to the increase in obesity in younger people, even children and young adults are now being diagnosed with type 2 diabetes.